How Fast Does Your PC Heat Up? Real Data on How Long to Stress Test

Start a stress test and your CPU temperature jumps 10°C in a second. A laptop races to 95°C, then drops back. A graphics card is still creeping up when the test ends. Is any of this a problem? And how long does a stress test really need to run?

Since ThermalStats CLI 2.1, every test records its full temperature curve: one reading per second, starting 10 seconds before the load. This article looks at 338 of those curves from ThermalStats users' own PCs and laptops — 291 CPU curves and 235 GPU curves.

Key Findings

• CPUs heat up almost instantly. Half of the temperature rise happened in the first 2–3 seconds of a full load. A sudden jump when a game starts is normal.
• Laptops level off twice as fast. The median laptop CPU came within 2°C of its peak after 28 seconds; the median desktop CPU took 55.5 seconds.
• 44% of laptop CPUs spike, then settle. They peaked about 17 seconds in, then fell a median 11.6°C — power limits at work, not a fault.
• GPUs climb more slowly. A 30-second test read at least 5°C below the 2-minute peak on 59% of desktop graphics cards.
• Two minutes is enough for most CPUs. A 1-minute test came within 5°C of the 2-minute peak on 85% of desktop CPUs and 93% of laptop CPUs.

The Typical Heat-Up Curve

These charts show the median temperature at each second of a 2-minute test, starting 10 seconds before the load.

CPUGPU

Show the data

Time (s)	CPU	GPU
-10	45	41
-8	45	41
-6	45	41
-4	44.6	41
-2	44.8	41
0	47.7	42
2	57.2	52
4	59	54
6	59.9	56
8	60.2	59
10	60.4	60
12	61	61
14	60.6	61
16	61	62
18	61.7	62
20	61.9	63
22	62.8	63
24	62	64
26	62.2	64
28	63	65
30	63	65
32	63	66
34	63	66
36	63.3	66
38	63.8	66
40	63.8	66
42	63.9	66
44	64	67
46	64	67
48	64	67
50	64	67
52	64	67
54	64	68
56	64.1	67
58	64.4	68
60	64.2	68
62	64.9	68
64	64.9	68
66	65	69
68	65	68
70	65	69
72	65	69
74	65.1	69
76	65	69
78	65.4	69
80	66	69
82	66	69
84	65.7	69
86	65.9	69
88	66	69
90	66	69
92	66	69
94	66	69
96	66.7	69
98	66.2	70
100	66.3	70
102	66.4	70
104	66.3	70
106	66.8	70
108	66.8	70
110	66.7	70
112	67	70
114	67	70
116	67	70
118	67.2	70

CPUGPU

Show the data

Time (s)	CPU	GPU
-10	56.6	—
-8	56.1	48.5
-6	56	47
-4	56	48
-2	56	49
0	60	49
2	69.1	53
4	70	56.5
6	68.5	59
8	69.4	61
10	70	61.5
12	70	63
14	71.5	64
16	72	65
18	72	66
20	73	67
22	73	67
24	73	68
26	74	68
28	74	68.5
30	75	69
32	74.9	69.5
34	75	69.5
36	75	69.5
38	74.9	70
40	75.1	70
42	75.4	70.5
44	75	71
46	75	71
48	75.9	71
50	76	72
52	76	72
54	76	72
56	76	72
58	76	72.5
60	76.3	73
62	76	72.5
64	75.5	72
66	75.5	72.5
68	76	72.5
70	75.9	72.5
72	76.1	72
74	76	72
76	76	72
78	76	72
80	76	72
82	76	72
84	76	72.5
86	75.5	72
88	75.5	72
90	76	72.5
92	76	72.5
94	76	72.5
96	75.6	72.5
98	75.5	72
100	76	72.5
102	76	72.5
104	76	72.5
106	76	72.5
108	76	73
110	76	72.5
112	76.5	73
114	76	73
116	76	73
118	76	73.5

The typical desktop CPU idles at 45°C, reaches 57°C two seconds into the test, then creeps up to 64°C at one minute and 67°C at two. The desktop GPU starts lower (41°C) but keeps climbing: 60°C after 10 seconds, 68°C at one minute and 70°C at the end. Laptop CPUs start at about 56°C, hit 69°C within two seconds and level off around 76°C.

The lines are medians, so they're smoother than any real run. Each system's own peak is a few degrees higher (a median 69°C for desktop CPUs and 83°C for laptop CPUs) because systems peak at different moments.

Why CPU Temperatures Jump in Seconds

A CPU makes its heat in a small piece of silicon. When a full load arrives, its power draw can jump from about 10 watts to over 100 watts at once, and that heat must cross the chip, the heat spreader and the thermal paste before the cooler can carry it away. The temperature difference across those layers appears almost immediately. Then comes the slower part: the heatsink or AIO liquid warms up and the fans speed up, which takes tens of seconds.

So the first seconds of a test say little about your cooler. What matters is where the temperature settles. Only 1.9% of desktop CPUs passed 90°C within the first 10 seconds.

Cooler type changes the timing. Desktop CPUs on AIO coolers came within 2°C of their peak after a median 32 seconds, tower air coolers after 46 seconds and stock coolers after 66 seconds. An AIO's liquid barely warms in two minutes, so most of its rise is the instant jump, while a small stock heatsink keeps warming. These groups are small (22–41 systems) and use different CPUs, so treat this as a tendency.

Why Laptops Spike, Then Settle

Show the data

Time (s)	CPU
-10	44
-8	46
-6	44
-4	44
-2	45
0	62
2	72
4	74
6	77
8	79
10	80
12	82
14	83
16	84
18	86
20	87
22	88
24	89
26	89
28	90
30	81
32	79
34	78
36	78
38	77
40	77
42	77
44	76
46	77
48	77
50	76
52	77
54	77
56	77
58	76
60	77
62	78
64	77
66	78
68	78
70	77
72	77
74	77
76	78
78	78
80	78
82	78
84	78
86	78
88	78
90	78
92	78
94	78
96	79
98	79
100	78
102	78
104	79
106	79
108	79
110	79
112	79
114	79
116	79
118	79

Most laptops have two power limits: a high one they can hold briefly and a lower one they can sustain. Intel calls them PL2 and PL1; AMD laptops use similar short- and long-term limits. The laptop runs at the high limit until a timer expires or it gets too hot, then drops to the sustained level, and the temperature follows.

44% of laptop CPUs peaked and then finished at least 5°C lower: a median peak 17 seconds in, followed by an 11.6°C drop. Only 11% of desktop CPUs did this, and they fell less (7.3°C), because many desktop motherboards let the CPU hold high power indefinitely.

What this means for you:

• A 95°C spike that falls back within a minute is normal. The settled temperature is what matters for long gaming or rendering sessions.
• If the settled temperature is also 95–100°C, the laptop is held back by heat rather than power, and cleaning, repasting or a cooling pad may help.

Why GPUs Take Longer

Graphics cards reached half of their rise after 6 seconds on desktops and 9 seconds on laptops, two to four times slower than CPUs. A GPU spreads its heat across a bigger chip and a heavy heatsink, and many desktop cards stop their fans at idle, so the fans ramp up gradually.

The result: a 30-second test read at least 5°C low on 59% of desktop GPUs and 64% of laptop GPUs, and 28% of desktop cards were still heating up when a 2-minute test ended.

How Long Should You Stress Test?

Part	Half of the rise	Within 2°C of peak	30 s test 5°C+ low	1 min test 5°C+ low	Still heating at 2 min
Desktop CPU (n=156)	3 s	55.5 s	39%	15%	17%
Laptop CPU (n=135)	2 s	28 s	28%	7%	10%
Desktop GPU (n=149)	6 s	56 s	59%	29%	28%
Laptop GPU (n=86)	9 s	55 s	64%	13%	16%

• 30 seconds is enough to spot a serious CPU cooling problem, but too short for a GPU. ThermalStats doesn't submit these quick tests to the database.
• 2 minutes, the ThermalStats default, shows a laptop's settled temperature and gets the typical CPU within about 2°C of a 5-minute peak.
• 5 minutes is better for graphics cards and for anything still heating up at the end of a 2-minute test. In our 5-minute runs, the extra time added a median 2°C to desktop CPU peaks and 1°C to desktop GPU peaks, but about 40% gained 3°C or more (17 CPU and 16 GPU runs).
• A long gaming session is still the best test of a case that slowly fills with warm air.

Your ThermalStats results page checks this for you: it says when each part came within 2°C of its peak, and warns you if it was still heating up when the test ended.

Three More Curve Shapes

Fast Rise, Then Flat

Show the data

Time (s)	CPU
-10	45.5
-8	45.4
-6	45.3
-4	45.3
-2	45.1
0	50.3
2	61.1
4	64.3
6	65.3
8	66.3
10	66.5
12	67.3
14	67.6
16	68
18	68.3
20	68.4
22	68.5
24	68.5
26	68.8
28	68.9
30	68.9
32	68.8
34	68.8
36	68.8
38	68.8
40	69
42	69
44	69
46	68.9
48	69
50	69
52	68.9
54	68.9
56	68.8
58	68.8
60	68.8
62	69
64	68.8
66	68.8
68	68.8
70	68.9
72	69
74	68.9
76	69
78	68.9
80	69
82	69
84	69
86	69.1
88	69
90	69
92	69
94	69.1
96	69.1
98	69.4
100	69.3
102	69.3
104	69.1
106	69.1
108	69.1
110	69.3
112	69.9
114	69.5
116	69.4
118	69.5

The healthy desktop shape: an instant jump, a gentle climb, then a flat line. This Ryzen 5 9600X jumped from 45°C to 61°C in two seconds and settled just under 70°C.

Still Climbing at the End

Show the data

Time (s)	GPU
-10	39
-8	39
-6	40
-4	39
-2	39
0	39
2	41
4	40
6	39
8	50
10	52
12	53
14	54
16	55
18	56
20	57
22	58
24	58
26	59
28	60
30	60
32	61
34	61
36	62
38	62
40	63
42	63
44	64
46	64
48	65
50	65
52	66
54	66
56	66
58	67
60	67
62	68
64	68
66	69
68	69
70	69
72	70
74	70
76	70
78	70
80	71
82	71
84	71
86	71
88	72
90	72
92	72
94	72
96	73
98	73
100	73
102	73
104	74
106	74
108	74
110	74
112	74
114	75
116	75
118	75

The heatsink, card or case is still warming up when the test stops, which is common for GPUs. Run a 5-minute test to see where it levels off. If it's still rising after that, check your fan curve and case airflow.

Straight to the Limit

Show the data

Time (s)	CPU
-10	43
-8	43
-6	44
-4	43
-2	43
0	43
2	82
4	90
6	92
8	94
10	96
12	96
14	97
16	100
18	100
20	100
22	100
24	100
26	100
28	99
30	99
32	100
34	100
36	100
38	100
40	100
42	100
44	99
46	99
48	99
50	99
52	100
54	100
56	100
58	100
60	99
62	100
64	99
66	100
68	100
70	100
72	99
74	100
76	99
78	100
80	98
82	100
84	100
86	99
88	100
90	100
92	100
94	100
96	100
98	100
100	100
102	100
104	100
106	100
108	99
110	100
112	100
114	100
116	99
118	100

The temperature hits the chip's maximum within seconds and stays there. Some high-end chips are built to do this: the Core i9-13900K and 14900K, and many Ryzen 7000 desktop chips, keep boosting until they reach their 95–100°C limit. This 13900K went from 43°C to 82°C in two seconds and reached 100°C after 16.

On a mid-range chip, the same shape usually points to a poor cooler mount, dried-out paste or an AIO pump that isn't running. See safe CPU and GPU temperatures for common chips' limits.

See Your Own Curve

Run the free ThermalStats CLI, version 2.1 or later. Your results page shows your full curve, and the temperature checker compares your peak with other owners of the same hardware. After cleaning, repasting or upgrading your cooler, run a before-and-after test to measure the difference.

How We Measured

• Source: 338 ThermalStats CLI 2.1+ tests with a temperature curve, submitted between September 26 and October 16, 2026. Readings come once per second (every two seconds in some longer tests), starting 10 seconds before the load.
• Cleaning: one curve per user per chip (the most recent). The stressed part must have passed 50% utilisation and warmed by at least 3°C. Desktops and laptops are separated as in our real-world temperature report.
• Same window: every curve is cut to its first 118 seconds of load, so 2-, 3- and 5-minute tests compare like for like. "Peak" is the highest reading in that window.
• Sensors: CPU package temperature; GPU hotspot where the card reports one, otherwise the core sensor.
• Limits: stress tests are a steady worst case, while games load hardware unevenly. This is three weeks of data; we'll update the article as more curves arrive.

Frequently Asked Questions

How long should I stress test my CPU and GPU?

Two minutes is enough for most CPUs: the median desktop CPU came within 2°C of its peak after 55.5 seconds. Give graphics cards 5 minutes if you can, and rerun any test whose temperature was still rising at the end.

Why does my CPU temperature spike instantly?

The heat is made in a small area of silicon, so the chip warms within a second or two, before the cooler can respond. Half of the total rise happened in the first 2–3 seconds. The settled temperature is what matters.

Why does my laptop hit 95°C and then drop?

Most laptops boost at a high power limit for a short time, then drop to a limit they can sustain. 44% of laptop CPUs in our data did this, falling a median 11.6°C.